Copper alloy



Patented May 27, 1941 2,243,278 COPPER ALLOY Franz R. Hansel and Ind., assignors to Indianapolis, ind, a

Earl L'Larscn, Indianapolis,

R. Mallory& 00., Ina.

corporation of Delaware No Drawing. Application March 9, 1939, Serial No. zed-us 2Claims.

and more parof improved characteris- This invention relates to alloys, ticularly copper alloys tics. g

The object of the invention is to produce an improved copper base alloy.

Another object is to produce a copper-magnesium alloy of comparatively low magnesium content, which can be improved by means of the addition of a small percentage of cadmium, to a higher degree than has heretoforebeen possible.

Another object is to produce a copper alloy which has an excellent combination of hardness, electrical conductivity, resistance to annealing, resistance to scaling and resistance to electrical erosion.

Specific objects are the provision of improved copper-cadmium-magnesium alloys, especially suit-able for fabrication into current carrying members, electrical contactors, welding electrodes, current carrying bearings, soldering irons, retainer rings, pole shaders, collector rings, small gears, switch blades, circuit breaker parts, internal combustion engine parts, turbine blades, parts which have to withstand oxidation and in general, parts which have to combine high thermal conductivity with high strength.

Other objects of the invention will be apparent from the following description, taken in connection with the appended claims.

The present invention comprises a combination of elements, methods of manufacture and the product thereof, brought out and exemplified in the disclosure hereinafter set forth, the scope of the invention being indicated in the appended claims.

out the present invention, an alloy is made containing copper, cadmium and magnesium, in the following proportions:

Per cent Cadmium .1 to,5 Magnesium -.05 to 3 Copper substantially the balance.

It is likewise possible to improve the characteristics of other copper-magnesium alloys, con taining small percentages of additional ingredients, by the addition of cadmium. I'hus, cop'- per-magnesium. alloys, tions of beryllium, calcium, zinc, silver, indium, boron, aluminum, silicon, titanium, zirconium, tin, lead, thorium, uranimn, lithium, phosphorus, vanadium, arsenic, selenium, .tellurium, manganese, iron, cobalt, nickel and chromium, can be improved by the addition of cadmium, in substantially the proportions indicated above.

A number of preferred compositions are given below:

Per cent (1) Magnesium .5 Cadmium 1 Copper Balance Per cen (2) Magnesium 1 Cadmium 2 Copper Balance (3) Magnesium uffi f f Cadmium .5 Copper Balance (4) Magnesium -332 Cadmium -1 Copper Balance (5) Magnesium -ffffi Cadmium 1 Chromium .50 Copper Balance The above compositions are given by example only and we have found that a large number of variations can be made, producing desirable results within the composition range specified.-

In carrying out the present invention; a copper-magnesium alloy may flrst be made according to the conventional alloy making procedure or the prior art, and then the silver may be added. After the alloy has been prepared according to such alloying methods as described above, also a heat treatment may be appliedto the alloys, consisting either in a quenching and subsequent aging operation, with working, or in a, quenching operation only, or in an" aging operation only; The quenching operations may be carried out at temperatures above 500 degrees C., and the drawing operations at temperatures below 500.

Magnesium has a solid solubility in copper. which decreaseswith temperature and therefore way of containing small propor or without intermediate .proved by heat treatment, usually called age hardening treaitment, as far as physical properties are concerned, and more particularly as far as thermal and electrical conductivity are concerned.

Copper-magnesium-cadmium alloys provide new materials which will retain their properties even at elevated temperatures.

If these materials are being used for contactor contacts, they will show a longer life than materials of the prior art and more particularly copper, andthey can be operated under more severe electrical loads, without causing fusing and sticking; At the same time, the contact resistance will remain low.- I y While the present invention as to its objects and advantages has been described herein, as carried out in specific embodiments thereof, it is not desired to be limited thereby, but it is intended to cover the invention broadly, within the spirit and the scopeof the appended claims,-

What is claimed is: v

1. an alloy containing about .5% magnesium, about 1% cadmium, about .5% chromium and the balance substantially all copper.-

2. An electric contacting element of the type comprising pressure exerting welding electrodes,

-contactor contacts and the like formed of an alloy containing about .5% magnesium, 1% cadmium, about .5% chromium and the balance substantially all copper.

I FRANZ R. HENSEL.

EARL I, LARSEN. 

